hmmm if i had to guess your concerned with ninty being able to see the apps you use and then do something malicious?

WELL just to put your mind at ease IT IS ILLEGAL FOR NINTY TO INSTALL DATA ON YOUR CONSOLE WITHOUT YOU PERSOANALLY ACCEPTIONG THAT INSTALL...so there really isnt shit they can do about it without being in more legal trouble than its worth to them....

But i would imagine doing a nand dump and using DOLPHIN to test your theories might be safer than dickin with the system menu files (but so long as your confident in brick recovery you could use the wii to experiment with that i have bricked COUNTLESS TIMES and recoverd making themes with no prob and i dont even use bootmii so...just preloader)

But if you guys do figure this out i am certain he is not the first and likely not the last to want a app deved that can "clean the nand messages up" i wonder how much data we use up over LONG periods of time (years) with all those messages?!

The ninty aspect is one of many.
In General, a Homebrew application which can manage the wii messages would be great.
Especially to backup messages, delete any messages (like the today play history, which cannot be deleted through the normal menu) and to create new messages.

Beware!!! It's dangerous to change Nand Files if you don't know what to do!!!
You should also make a backup of your system!!!

Dumping \title00000010000002\data\cdb.vff of the Wii Nand.

Open cbd.vff with a HexEditor.
The first lines are the declaration of numbers, symbols and letters. So don't touch it.
The messages begin at 002A020 (Hex Offset).
Every "Today's Play History" Message begins with Hex Code:
43444246494C45023C0762FBDF3E798A0C000000706C617974696D656C6F6700
(ASCII: CDBFILE.yŠ....playtimelog.)

So, you can change the text of the today's play history between the flag and the total playtime.

A Today's Play History has always the same size. Independent how many games, channels you used.
(Length 1800 Byte)

If you change something at the duration of the playtime the Today's play History for this day will reset.

Don't erase a complete message. The message board won't show up the message (cause you deleted it) but the message box shows that you have one message.
After you start/quit a channel and check the message board, no message will appear, too.
So the amount of messages in the message box must be handled elsewhere in the system.

i just made a copy of the message board before i ever played anything on the wii (new wii->bannerbomb->nand dump). then you can do whatever you want and when you want to have a clean message board, just slap the new one back in there.